Ballpoint pen



FIG. 1 is a perspective view of a ballpoint pen according to my design;

FIG. 2 is a front view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left side view thereof,

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a top view thereof.

The ornamental design for a ballpoint pen, as shown and described. 